JP5794424B2 - Swing forging device and swing forging method - Google Patents

Description

  The present invention relates to a swing forging device and a swing forging method.

Conventionally, a swing forging method has been used as one method for forming a disk-shaped part. This swing forging method is a swing forcing provided with a swing portion and a lifting portion as will be described below. This is realized by a forging device. Here, the oscillating portion is for oscillating and rotating (so-called “rubbing motion”), for example, an upper die having a conical angle with respect to a predetermined center point. Moreover, the raising / lowering part raises / lowers the lower mold relative to the upper mold.
The specific forming procedure using the swing forging device is as follows. First, set a disk-shaped or columnar workpiece on the lower mold, raise the lower mold, and bring the workpiece into contact with the upper mold that swings and rotates. Let As the upper mold swings and rotates, the workpiece molding proceeds sequentially in the circumferential direction. As the molding of the workpiece progresses, the vertical distance between the upper mold and the lower mold approaches and is held at a constant distance. Then, in a state where the upper mold and the lower mold are held at a certain distance, the workpiece is held for a predetermined time while continuing the swinging and rotating motion of the upper mold, and then the lower mold is lowered to complete the molding. . According to such a swing forging method, impact and vibration are less generated than in a general forging method, and the internal stress of the work can be reduced, so that the final product shape can be forged in one cycle. (For example, see Patent Documents 1 and 2).

JP-A-5-337581 JP 59-73138 A

FIG. 9A shows a workpiece W having a cylindrical portion Wa with a virtual line together with the upper die 12 and the lower die 14 of the conventional swing forging device. Axis shown by reference numeral C _V in the figure represents a vertical axis (vertical central axis of the lower mold 14), the axis indicated by reference numeral C ₁₂ in the figure, shows the swing axis of rotation of the upper mold 12 Yes. By the way, in order to perform swing forging on a disk-shaped workpiece W having a cylindrical portion Wa as shown in the figure, the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W is shown in FIG. As shown, when the frustoconical protrusion 12a of the upper mold 12 is brought into contact, the inner peripheral surface Wb is not sufficiently restricted by the protrusion 12a. As a result, the surplus portion Wd is generated so that the portion not constrained by the protrusion 12a damages the originally required inner peripheral surface Wc. Therefore, a post process for removing the surplus portion Wd is indispensable.

On the other hand, as shown in FIG. 9B, the upper mold 12 is provided with a columnar protrusion 12a ′ that can restrain the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W in a wider range. When provided and swing forging is performed, a problem different from the above occurs. That is, the swing forging method differs from the general forging process, the upper mold 12 performs a swinging motion drives out swinging rotary shaft C ₁₂ inclined with respect to the vertical axis Cv. For this reason, a large bending moment M is generated in the cylindrical protrusion 12a ′ along with the swinging and rotating movement of the upper mold 12, and the upper mold 12 may be damaged. Such a problem is that the columnar protrusion 12 a ′ has a structure that is integrated with the upper mold 12, or is a so-called separate structure from the upper mold 12 that is detachably fixed to the upper mold 12. Even the plug type can occur similarly.
The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to prevent the mold from being damaged when performing rocking forging on a workpiece having a cylindrical portion, and the cylinder. An object of the present invention is to enable molding into a desired shape without causing surplus on the inner peripheral surface of the shape portion.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

(1) A disc-shaped workpiece having a first die, a swinging portion that swings and rotates the first die with reference to a predetermined center point, and a cylindrical portion having a multi-stage inner peripheral surface is set. A second mold to be formed, an elevating part for bringing the second mold and the first mold apart and approaching each other and bringing the workpiece into contact with the first mold, and an inner peripheral surface of the cylindrical portion of the workpiece. Therefore, the outer peripheral shape of the plug mold is a multi-stage cylindrical shape following the inner peripheral surface of the cylindrical portion of the workpiece. The plug mold is inserted into the inner peripheral surface of the cylindrical portion of the workpiece, so that the center axis of the workpiece and the center axis of the plug mold coincide with each other. The second mold has a molding surface related to a disk-shaped part of the work and a through hole into which the cylindrical part of the work is inserted. By being serial set in the second type, by interposing the workpiece, the plug-type central axis of, is centered with respect to the vertical direction center axis of the second type, the plug-type has its central axis Is supported from below through the work so as to be able to come into contact with the first mold together with the work while maintaining the centered state with respect to the vertical central axis of the second mold. Swing forging device (Claim 1).

The swing forging device described in this section is configured such that, for example, the second die is moved up and down with respect to the first die while the first die is driven to rotate with respect to a predetermined center point. And the first mold are separated and approached. In addition, with the disk-shaped workpiece having a cylindrical portion having multi-stage inner peripheral surfaces set in the second die, the second die is raised, and the workpiece is brought into contact with the first die that oscillates and rotates. As a result of the contact, the disk-shaped workpiece set in the second mold is sequentially formed in the circumferential direction along with the swinging and rotating movement of the first mold.
In addition, the invention of this section includes a plug mold for molding the inner peripheral surface of the cylindrical portion of the workpiece, and this plug mold is separate from the first mold and the second mold. And while the center axis | shaft maintains the state centered with respect to the vertical direction center axis | shaft of a 2nd type | mold, it is supported from the bottom so that it can contact | abut with a 1st type | mold with a workpiece | work. That is, the plug type is not firmly restrained by either the first type or the second type, and the plug type changes the relative position with respect to the first type as appropriate during the swinging and rotating movement of the first type. Is. More specifically, the plug type does not operate integrally with the first type of oscillating rotational movement, and does not perform passive operations such as so-called revolving. Since the relative position between the plug mold and the first mold is changed in such a manner that the centered state with respect to the central axis in the vertical direction is maintained, no large bending moment is generated in the plug mold. Moreover, since the center axis of the plug mold is centered with respect to the vertical center axis of the second mold, the plug mold is inadvertently displaced , and the multi-stage of the cylindrical portion of the workpiece is This does not impair the molding accuracy of the inner peripheral surface on which the inner peripheral surface is formed . And since the plug mold is for molding the inner peripheral surface of the cylindrical portion of the workpiece, the plug mold is sufficient to restrain the inner peripheral surface of the cylindrical portion of the workpiece, and a surplus portion is generated. The originally required shape is not lost.

Furthermore , the outer peripheral shape of the plug mold is a multi-stage cylindrical shape that follows the inner peripheral surface of the cylindrical portion of the workpiece. By inserting the plug mold into the inner peripheral surface of the cylindrical portion of the workpiece, The center axis of the plug and the center axis of the plug type coincide with each other. In addition, the second mold has a molding surface relating to the disk-shaped part of the work and a through hole into which the cylindrical part of the work is inserted. By setting the work in the second mold, The center axis of the plug type is aligned with the center axis of the second type in the vertical direction. Then, without relative positional relationship with respect to the first type of plug-type is restricted by the first type, is supported from below by interposing the workpiece, and a second type in a state where the workpiece is set to the second type first The workpiece is brought into contact with the first die that is swung and rotated by bringing the first die closer. As a result, the disk-shaped workpiece set in the second mold is sequentially formed in the circumferential direction along with the swinging and rotating motion of the first mold, and the inner circumferential surface of the cylindrical portion of the workpiece is multistage. Also on the inner peripheral surface on which the plug is formed, molding by the plug mold proceeds sequentially.

( 2 ) In the above ( 1 ), a swing forging device comprising positioning means for positioning the plug mold together with the workpiece in a state of being pressed against the first mold (claim 2 ).
In the swing forging device described in this section, the workpiece is brought into contact with the first die that swings and rotates by bringing the second die and the first die closer to each other while the workpiece is set in the second die. Further, the positioning means is used to position the plug mold together with the workpiece in a state of being pressed against the first mold. Accordingly, the molding of the workpiece set in the second die proceeds sequentially in the circumferential direction along with the swinging and rotating motion of the first die, and the inner peripheral surface of the cylindrical portion of the workpiece is also dependent on the plug die. Molding proceeds sequentially.

( 3 ) The swing forging device according to the above ( 2 ), comprising a sleeve that penetrates the second die in the vertical direction and holds the cylindrical portion of the workpiece from below.
In the swing forging device described in this section, the plug die is inserted into the cylindrical part of the workpiece, and the workpiece is set in the second die by the sleeve penetrating the second die in the vertical direction. The cylindrical portion is held from below.

( 4 ) In the above ( 3 ), the positioning means includes a biasing means that is inserted through the sleeve and biases the plug mold upward (Claim 3 ).
In the swing forging device described in this section, the plug mold is inserted into the cylindrical portion of the workpiece and the plug mold is moved upward by the biasing means of the positioning means in a state where the workpiece is set in the second mold. It is biased and positioned in a state where it is pressed against the first mold. The plug mold is urged upward by the urging means so that the plug mold is simply inserted into the cylindrical portion of the work and the work is set to the second mold. Separates and protrudes upward. When the second mold and the first mold are brought close to each other in this state, the plug mold comes into contact with the first mold before the work, and the work comes into contact with the first mold with a delay.

( 5 ) In the above items (1) to (4), the first mold is provided with a recess for fitting the upper end of the plug mold with a gap allowing the rocking rotation. A swing forging device (Claim 4 ).
In the swing forging device described in this section, the plug mold is fitted into the recess provided in the first mold with a gap at which the upper end of the plug mold allows rocking rotation. While changing the relative positional relationship with respect to the first mold in accordance with the swinging and rotating motion of the first mold, it is supported from below so that it can come into contact with the first mold together with the workpiece. In addition, a gap is formed sequentially in the circumferential direction in the gap between the upper end of the plug mold and the first mold in conjunction with the rocking rotation, but the gap is hidden in the recess provided in the first mold. Thus, it is possible to avoid the surplus workpiece fluid from flowing into the gap. Therefore, it is possible to avoid that the work surplus becomes an undercut portion and partially covers the upper end portion of the plug mold so that the work cannot be released from the plug mold.

( 6 ) The first mold is swung and rotated with a predetermined center point as a reference, and a disk-shaped workpiece having a cylindrical portion having a multi-stage inner peripheral surface is set on the second mold. A rocking forging method in which the workpiece is formed by bringing the workpiece into contact with the first die by moving away from and approaching the second die, and is separate from the first die and the second die. The plug mold is formed so that the outer peripheral shape thereof is a multistage cylindrical shape following the inner peripheral surface of the cylindrical portion of the workpiece, and the plug mold is inserted into the inner peripheral surface of the cylindrical portion of the workpiece. Thus, the center axis of the work and the center axis of the plug mold coincide with each other, and the molding surface related to the disk-shaped part of the work and the cylindrical part of the work are inserted into the second mold. Forming a hole, and setting the work in the second mold so that the center of the plug mold is interposed via the work. And then combined core with respect to the vertical direction center axis of the second type, the plug-type, the center axis thereof, while maintaining the centering state with respect to the vertical direction center axis of the second type, The swing is characterized in that the inner peripheral surface of the cylindrical portion of the work is formed by the plug mold so that the work can be brought into contact with the first mold together with the work and supported from below. Dynamic forging method (Claim 5 ).

In the swing forging method described in this section, the second die is moved up and down with respect to the first die in a state where the first die is driven to swing and rotate with a predetermined center point as a reference. And the first mold are separated and approached. In addition, a disk-shaped workpiece having a cylindrical portion with a multi-stage inner peripheral surface set in the second mold is brought into contact with the first mold that swings and rotates, thereby allowing the first mold to swing. Along with the dynamic rotational movement, the molding of the workpiece set in the second mold is sequentially advanced in the circumferential direction. Then, as the molding of the workpiece proceeds, the vertical distance between the first mold and the second mold is made closer, and the first mold and the second mold are held at a constant distance by a mechanical stopper or the like, and further Molding is completed after performing one type of rocking rotation.
Moreover, in the invention of this section, a plug mold for forming the inner peripheral surface of the cylindrical portion of the workpiece, which is separate from the first mold and the second mold, is used. And while maintaining the state which centered the center axis | shaft of the plug type | mold with respect to the vertical direction center axis | shaft of the 2nd type | mold, it supports from the downward direction so that it can contact | abut with a 1st type | mold with a workpiece | work. In other words, the plug mold changes its position relative to the first mold as needed during the swinging and rotating movement of the first mold without firmly constraining the plug mold to either the first mold or the second mold. It is. More specifically, the plug type does not operate integrally with the first type of oscillating rotational movement, and does not perform passive operations such as so-called revolving. Since the centered state with respect to the direction center axis is maintained and the relative position of the plug mold and the first mold is changed, a large bending moment is not generated in the plug mold. Moreover, since the center axis of the plug mold is centered with respect to the vertical center axis of the second mold, the plug mold is inadvertently displaced , and the multi-stage of the cylindrical portion of the workpiece is This does not impair the molding accuracy of the inner peripheral surface on which the inner peripheral surface is formed . And since the plug mold is for molding the inner peripheral surface of the cylindrical portion of the workpiece, the plug mold is sufficient to restrain the inner peripheral surface of the cylindrical portion of the workpiece, and a surplus portion is generated. The originally required shape is not lost.

Furthermore , by forming the outer peripheral shape of the plug mold so as to be a multistage cylindrical shape following the inner peripheral surface of the cylindrical portion of the workpiece, by inserting the plug mold into the inner peripheral surface of the cylindrical portion of the workpiece, Match the center axis of the workpiece with the center axis of the plug type. In addition, a molding surface for a part of the workpiece that is disk-shaped and a through hole into which the cylindrical portion of the workpiece is inserted are formed, and the workpiece is set in the second die so that the workpiece is interposed. the central axis of the plug type, is to fit the core with respect to the vertical direction center axis of the second type. Then, the relative positional relationship of the plug mold with respect to the first mold is not restricted by the first mold, and is supported from below with the work interposed therebetween. The work is brought into contact with the first mold that is swung and rotated by bringing the first mold close to the first mold. As a result, the disk-shaped workpiece set in the second die is sequentially formed in the circumferential direction in accordance with the swinging and rotating motion of the first die, and the multi-stage inner peripheral surface of the cylindrical portion of the workpiece As for the inner peripheral surface on which is formed, molding by the plug mold is sequentially advanced.

( 7 ) The swing forging method according to (6 ) above, wherein the plug mold is positioned in a state of being pressed against the first mold together with the workpiece (claim 6 ).
In the swing forging method described in this section, the workpiece is brought into contact with the first die that swings and rotates by bringing the second die and the first die closer to each other while the workpiece is set in the second die. Furthermore, the plug mold is positioned in a state of being pressed against the first mold together with the workpiece. Thereby, with the rocking rotation of the first mold, the molding of the workpiece set in the second mold is sequentially advanced in the circumferential direction, and the inner peripheral surface of the cylindrical portion of the workpiece is also formed by the plug mold. Molding proceeds sequentially.

( 8 ) In the above item (6) (7) , the first mold is provided with a recess for fitting the upper end of the plug mold with a clearance allowing the rocking rotation, and the recess is provided in the recess. A swing forging method in which the upper end of the plug mold is inserted and held (Claim 7 ).
In the swing forging method described in this section, the upper end of the plug mold is fitted into the recess provided in the first mold with a gap that allows rocking rotation. While changing the relative positional relationship with respect to the first mold according to the swinging and rotating motion of the first mold, it is supported from below so that it can come into contact with the first mold together with the workpiece. In addition, a gap is formed sequentially in the circumferential direction in the gap between the upper end of the plug mold and the first mold in conjunction with the rocking rotation, but the gap is hidden in the recess provided in the first mold. Thus, it is possible to avoid the surplus workpiece fluid from flowing into the gap. Therefore, it is possible to avoid that the work surplus becomes an undercut portion and partially covers the upper end portion of the plug mold so that the work cannot be released from the plug mold.

  Since the present invention is configured as described above, when performing rocking forging on a workpiece having a cylindrical portion, there is no damage to the mold, and extra space is generated on the inner peripheral surface of the cylindrical portion. It becomes possible to form into a desired shape.

It is principal part sectional drawing of the rocking forge device which concerns on embodiment of this invention. It is the exploded view which showed the structure of the metal mold | die of the rocking forge device which concerns on embodiment of this invention with the partial cross section figure. (A)-(c) is sectional drawing which shows the procedure which shape | molds the workpiece | work which has a cylindrical part using the metal mold | die shown by FIG. (A)-(c) is sectional drawing which shows the rocking | fluctuation rotation motion of an upper mold | type at the time of shape | molding the workpiece | work which has a cylindrical part using the metal mold | die shown in FIG. FIGS. 3A and 3B are diagrams showing a state at the time of forming start on the right half and a state at the end of forming on the left half when forming a workpiece having a cylindrical portion using the mold shown in FIG. 2. When forming a workpiece having a cylindrical portion using the mold shown in FIG. 2, the recess provided in the upper die and the upper end portion of the plug die are opened with a gap that allows swinging rotation. It is an enlarged view which shows a mode that it fits. FIG. 2A shows the effect obtained by fitting the recess shown in FIG. 2 with the recess provided in the upper mold and the upper end of the plug mold with a clearance allowing swinging rotation. It is explanatory drawing, (b) is explanatory drawing which shows the example which abbreviate | omitted the upper mold | type recessed part. It is explanatory drawing which shows the method of releasing a workpiece | work from a plug type | mold, after shape | molding the workpiece | work which has a cylindrical part using the metal mold | die shown in FIG. (A), (b) is the figure which showed the other example from which the upper mold | type structure differs of the conventional rocking forging apparatus with a partial cross section figure.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the following description, parts that are the same as or correspond to those in the prior art are assigned the same reference numerals, and detailed descriptions thereof are omitted.

FIG. 1 is a cross-sectional view of the main parts of the swinging part and the lifting part of the swing forging device according to the embodiment of the present invention. The oscillating forging device 10 includes an oscillating part 16 and an elevating part 18, and the oscillating part 16 holds the upper mold 12 as a first mold and holds the upper mold 12 in the present embodiment. Oscillating and rotating with respect to the center point. Further, as the second mold for setting the workpiece W having the cylindrical portion Wa (see FIG. 2), the elevating unit 18 raises and lowers the lower mold 14 relative to the upper mold 12 in the present embodiment, thereby moving the workpiece W. This is brought into contact with the upper mold 12. Furthermore, the embodiment of the present invention includes a plug mold 20 for forming the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W, which is separate from the upper mold 12 and the lower mold 14.
FIG. 1 shows two states (before starting molding and during molding) of the swinging portion 16 and the lifting / lowering portion 18. Further, as shown in the figure, the swinging portion 16 may be lifted and lowered with respect to the lifting and lowering portion 18, and as described above, the lifting and lowering portion 18 operates so as to be lifted and lowered with respect to the swinging portion 16. Thus, a configuration may be employed in which the lower mold 14 is raised and the workpiece W is brought into contact with the upper mold 12 that performs the swinging and rotating motion. In the present embodiment, the following will be described by taking the latter as an example.

FIG. 2 shows the upper mold 12, the lower mold 14, the plug mold 20, and related members according to the embodiment of the present invention. The plug mold 20 has a center axis aligned with the vertical center axis Cv of the lower mold 14, and the relative positional relationship with the upper mold 12 is not restricted by the upper mold 12. , And is supported from below so as to be able to contact the upper mold 12 together with the workpiece W.
Here, the plug mold 20 has a multistage cylindrical shape in the illustrated example, and is inserted into the cylindrical portion Wa of the work W, and the work W is set on the lower mold 14, whereby the center of the plug mold 20 is formed. The axis is aligned with the vertical center axis Cv of the lower mold. In order to make this alignment possible, the outer peripheral shape of the plug mold 20 has a shape that follows the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W, and the plug mold 20 is a cylindrical portion of the workpiece W. By being inserted into the inner peripheral surface Wb of Wa, the center axis of the workpiece W and the center axis of the plug mold 20 are in agreement. The lower die 14 has a molding surface 14a and a through hole 14b into which the cylindrical portion Wa of the workpiece W is inserted. Then, when the workpiece W is set on the lower mold 14, the center axis of the plug mold 20 is aligned with the vertical center axis Cv of the lower mold with the workpiece W interposed.
Further, the plug mold 20 is formed so that the lower end portion 20b of the plug mold 20 protrudes from the cylindrical portion Wa of the workpiece W while being inserted into the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W before and after molding. (See FIG. 8).

  Further, as positioning means 22 for positioning the plug mold 20 together with the workpiece W against the upper mold 12, an urging means 24 for urging the plug mold 20 upward and a lower mold 14 are moved up and down. And a sleeve 26 that penetrates in the direction and holds the cylindrical portion Wa of the workpiece W from below. In the illustrated example, the sleeve 26 is a cylindrical member having an outer diameter that is in sliding contact with the through hole 14 b, and a coil spring that constitutes the biasing means 24 is inserted into the inner cylindrical portion 26 a of the sleeve 26. Thus, upward elastic force is applied to the lower end portion 20b of the sleeve 26 in a state of being inserted into the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W.

The sleeve 26 also has a function as an ejector for releasing the plug mold 20 and the workpiece W integrally as the sleeve 26 rises with respect to the lower mold 14. The operation of the sleeve 26 is performed by a hydraulic cylinder or the like provided in the elevating unit 18. Further, the biasing means 24 is not limited to the illustrated coil spring, and other elastic members may be used as necessary to generate an arbitrarily controlled upward biasing force such as a linear actuator. It is also possible to use means.
Further, as will be described later, the upper die 12 has a recess 28 for fitting the upper end portion 20a of the plug die 20 with a gap (see reference numeral S in FIG. 6) that allows the rotation to swing. Is provided.

Further, a chamfered portion 20c is formed in the upper end portion 20a of the plug mold 20 in order to ensure a gap (see reference numeral S in FIG. 6) that can allow swinging rotation. Further, the end surface of the upper end portion 20a is centered so that the plug die 20 is not subjected to excessive radial force that causes the center axis of the plug die 20 to be swung by the swinging and rotating movement of the upper die 12. The inclination angle of the constant range Ac close to the portion is set to be moderate (for example, the inclination angle with respect to a plane orthogonal to the vertical axis Cv is 2 °), and the inclination angle of the outer peripheral portion Ad is steeper than that (for example, the vertical axis Cv) The inclination angle with respect to a plane orthogonal to the angle is 5 °. Therefore, when the upper mold 12 swings and rotates, the upper mold 12 contacts the upper mold 12 only within a certain range Ac near the center.
In the illustrated example, the upper end portion 20a of the plug mold 20 has a gentle convex spherical shape, and the concave portion 28 provided in the upper mold 12 has a concave spherical surface that follows the end face of the upper end portion 20a of the plug mold 20. ing. However, as long as the good contact state with the upper end portion 20a of the plug mold 20 is maintained during the swinging and rotating motion of the upper mold 12, either one may be a flat surface.

Next, the swing forging method according to the embodiment of the present invention will be described with reference to FIGS.
First, the plug mold 20 is inserted into the cylindrical portion Wa of the workpiece W. 3A, the lower die 14 is sufficiently lowered with respect to the upper die 12 (bottom dead center), and the sleeve 26 is within the through hole 14b of the lower die 14. The workpiece W is set on the lower mold 14 while being held at an appropriate height for holding the lower end portion of the cylindrical portion Wa of the workpiece W from below. At this time, as shown in FIG. 3A, the coil spring constituting the urging means 24 is inserted into the inner cylindrical portion 26 a of the sleeve 26 and protrudes upward from the sleeve 26. Therefore, when the plug mold 20 is inserted into the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W, the urging means 24 comes into contact with the lower end portion 20b of the plug mold 20 so that the plug mold 20 is moved upward. The elastic force is energized and pushed upward so as to be separated from the workpiece W.
Normally, when the work W is set on the lower mold 14, the upper mold 12 is in a state of swinging and rotating, and the work W is set and removed from the lower mold 14 using a robot or other transfer machine. Done unattended.

Subsequently, as shown in FIG. 3B, the lower mold 14 is raised with respect to the upper mold 12. Then, in a state where the plug mold 20 is spaced apart and protrudes upward from the workpiece W, the plug mold 20 comes into contact with the upper mold 12 before the workpiece W, and the coil spring constituting the biasing means 24 is contracted, so that the plug mold 29 The workpiece W comes into contact with the upper mold 12 after a delay. As a result, the plug mold 20 is pushed into the cylindrical portion Wa of the workpiece W. And the center axis | shaft contact | abuts to the internal peripheral surface Wb of the cylindrical part Wa of the workpiece | work W, centering with respect to the vertical direction central axis Cv of the lower mold | type 14. FIG. Further, as shown in the right half of FIG. 5, a gap (see symbol S in FIG. 6) that allows the upper end portion 20 a of the plug die 20 to swing and rotate is opened in the recess 28 provided in the upper die 12. And fit.
Then, with the workpiece W in contact with the upper mold 12 that swings and rotates, as shown in FIGS. 4A to 4C, the upper mold 12 swings and rotates. Accordingly, the molding of the workpiece W set on the lower mold 14 proceeds sequentially in the circumferential direction. When the position of the upper mold 12 with respect to the lower mold 14 shown in FIG. 4A is 0 °, the phase of the upper mold 12 in FIG. 4B is 90 °, and the upper mold in FIG. The phase of 12 is 180 °. Further, from the molding start time shown in the right half of FIG. 5 to the molding end time shown in the left half, the plug mold 20 is always directed toward the upper mold 12 (recess 28) by the biasing means 24. The state of close contact with the upper mold 12 is maintained.

Thereafter, when the workpiece W is formed to a predetermined thickness, the lower mold 14 is lowered. Further, the sleeve 26 is raised with respect to the lower mold 14, and the plug mold 20 and the work W are released from the lower mold 14 together. And as FIG. 8 shows, the plug type | mold 20 and the workpiece | work W are set | placed (or dropped) on flat surfaces, such as the table 30, with the integrated state. Then, the plug mold 20 is in a state where the lower end portion 20b of the plug mold 20 protrudes from the cylindrical portion Wa of the workpiece W while being inserted into the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W even at the end of molding. Therefore, the plug mold 20 is pushed upward from the cylindrical portion Wa of the workpiece W, and the plug mold 20 is separated from the workpiece W.
The separation of the plug mold 20 and the work W from the lower mold 14, the separation work of the plug mold 20 and the work W, and the transfer work of the separated plug mold 20 and the work W are appropriately performed using a robot. Done.

Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained.
First, according to the embodiment of the present invention, the lower mold 14 is lifted in a state where the workpiece W is set on the lower mold 14, and the workpiece W is brought into contact with the upper mold 12 that swings and rotates. As the upper die 12 swings and rotates, the molding of the workpiece W set on the lower die 14 proceeds sequentially in the circumferential direction.

  Moreover, the plug mold 20 for forming the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W is separate from the upper mold 12 and the lower mold 14. The center axis of the lower mold 14 is aligned with the vertical center axis Cv of the lower mold 14 and the relative positional relationship with respect to the upper mold 12 is determined according to the swinging and rotating motion of the upper mold 12. While changing, it is supported from below so that it can contact the upper mold 12 together with the workpiece W. That is, the plug mold 20 is not firmly restrained by either the upper mold 12 or the lower mold 14, and the plug mold 20 changes its position relative to the upper mold 12 when the upper mold 12 swings and rotates. To go. Then, the plug mold 20 does not operate integrally with respect to the oscillating rotational movement of the upper mold 12, and does not perform passive operations such as so-called revolving. Since the centered state with respect to the axis Cv is maintained, no large bending moment is generated in the plug mold 20. Moreover, since the plug axis 20 is centered with respect to the vertical center axis Cv of the lower mold 14, the plug mold 20 is inadvertently displaced and the cylindrical shape of the workpiece W is formed. It does not impair the molding accuracy of the inner peripheral surface Wb of the portion Wa. Since the plug mold 20 is for molding the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W, the plug mold 20 is sufficiently restricted by the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W. Become. Therefore, the surplus portion Wd as shown in FIG. 5 does not occur and the originally required shape of the inner peripheral surface Wb cannot be obtained.

The outer peripheral shape of the plug mold 20 is a multi-stage cylindrical shape that follows the inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W, and the plug mold 20 has an inner peripheral surface Wb of the cylindrical portion Wa of the workpiece W. The center axis of the workpiece Wa and the plug type center axis coincide with each other. Further, the lower die 14 has a molding surface related to the disk-shaped portion of the workpiece W and a through hole 14b into which the cylindrical portion Wa of the workpiece W is inserted, and the workpiece W is set in the lower die 14. In this way, the center axis of the plug mold 20 is aligned with the vertical center axis Cv of the lower mold 14 with the workpiece W interposed therebetween . And the relative positional relationship with respect to the upper mold 12 of the plug mold 20 is not restricted by the upper mold 12, and the relative positional relation with respect to the upper mold 12 of the plug mold 20 according to the swinging and rotating motion of the upper mold 12. The plug mold 20 is supported from below by the lower mold 14 with the workpiece W interposed between them, and the workpiece W is brought into contact with the upper mold 12 that swings and rotates. Accordingly, the disk-shaped workpiece W set on the lower die 14 is sequentially formed in the circumferential direction along with the swinging and rotating motion of the upper die 12, and the multi-stage of the cylindrical portion Wa of the workpiece W is increased . Also with respect to the inner peripheral surface Wb on which the inner peripheral surface is formed, molding by the plug mold 20 proceeds sequentially.

  Further, the lower die 14 is raised with the workpiece W set on the lower die 14, and the workpiece W is brought into contact with the upper die 12 that swings and rotates. Position 20 in a state where it is pressed against the upper mold 12. As a result, as the upper mold 12 swings and rotates, the molding of the workpiece W set on the lower mold 14 proceeds sequentially in the circumferential direction, and the inner circumferential surface Wb of the cylindrical portion Wa of the workpiece W is also increased. Then, the molding by the plug mold 20 proceeds sequentially.

Further, during the molding process, the plug mold 20 is inserted into the cylindrical portion Wa of the workpiece W, and the plug mold 20 is inserted into the lower mold 14 by the biasing means 24 of the positioning means 22. It is biased upward and positioned in a state of being pressed against the upper mold 12.
Further, during the molding step, the plug mold 20 is inserted into the cylindrical portion Wa of the work W, and the work W is set on the lower mold 14, and the sleeve 26 penetrates the lower mold 14 in the vertical direction. The cylindrical portion Wa of W is held from below. The sleeve 26 not only supports the workpiece W at an appropriate position during the molding process, but also functions as an ejector when the workpiece W is released from the lower mold 14.

Further, in the embodiment of the present invention, the upper end 20a of the plug mold 20 is fitted into the recess 28 provided in the upper mold 12 with a clearance S (see FIG. 6) that can allow the rocking rotation. To do. Therefore, the plug mold 20 can come into contact with the upper mold 12 together with the workpiece W while changing the relative positional relationship with respect to the upper mold 12 according to the swinging and rotating motion of the upper mold 12 from below. It will be supported.
In addition, a gap S is sequentially formed in the circumferential direction in the gap between the upper end 20a of the plug mold 20 and the upper mold 12 in conjunction with the swinging rotation, but the gap S is a recess provided in the upper mold 12. It is hidden in 28. Therefore, as shown in FIG. 7A, it is possible to avoid the surplus wall of the workpiece W from flowing in the gap S. Note that an arrow F in FIG. 7A indicates that a surplus flow flows between the inner peripheral surface Wb of the workpiece W and the wall surface of the plug mold 20.

Therefore, the surplus Wd of the workpiece W (see FIG. 6) becomes an undercut portion, partially covers the upper end portion 20a of the plug mold 20, and the workpiece W cannot be released from the plug mold 20. It can be avoided.
As shown in FIG. 7B, the shape of the upper end portion (for example, the chamfered portion 20c) of the plug die 20 and the shape of the surface of the upper die 12 facing the plug die 20 are appropriately adjusted. By doing so, it is also possible to avoid the surplus flow F in which the surplus part of the workpiece W becomes an undercut part and partially covers the upper end part 20a of the plug mold 20. In this case, the concave portion 28 of the upper mold 12 can be omitted.
Further, as long as the relative positional relationship of the plug mold 20 with respect to the upper mold 12 is not restricted by the upper mold 12 and can be brought into contact with the upper mold 12 together with the workpiece W, the plug mold 20 and the upper mold 12 can be connected with a connecting portion having a complementary relationship in which a convex portion is provided on one side and a concave portion is provided on the other side, such as a ball joint. It is possible to obtain the operational effects.

  10: swing forging device, 12: upper die, 14: lower die, 20: plug die, 20a: upper end, 20b: lower end, 22: positioning means, 24: biasing means, 26: sleeve, 28: recess , W: work, Wa: cylindrical portion, Wb: inner peripheral surface

Claims (7)

A first part and a swinging part that swings and rotates the first mold with reference to a predetermined center point;
A second mold for setting a disk-shaped workpiece having a cylindrical portion formed with a multi-stage inner peripheral surface , and the second mold and the first mold are separated and approached to make the workpiece the first mold. An elevating part to abut,
Including a plug mold that is separate from the first mold and the second mold, for molding the inner peripheral surface of the cylindrical portion of the workpiece,
The outer peripheral shape of the plug mold is a multistage cylindrical shape following the inner peripheral surface of the cylindrical portion of the workpiece, and the plug mold is inserted into the inner peripheral surface of the cylindrical portion of the workpiece. The center axis of the workpiece and the center axis of the plug type are in agreement with each other,
In addition, the second mold has a molding surface relating to a disk-shaped part of the work and a through hole into which the cylindrical part of the work is inserted, and the work is set in the second mold. Then, with the workpiece interposed, the center axis of the plug type is aligned with the center axis of the vertical direction of the second type,
The plug mold is interposed so that the center axis of the plug mold can be brought into contact with the first mold together with the workpiece while maintaining a state where the center axis is aligned with the vertical center axis of the second mold. The swing forging device is supported from below. Wherein for positioning the plug-type to the state pressed against the first mold with the work, the swing forging apparatus according to claim 1, characterized in that it comprises positioning means. The positioning means includes a sleeve that vertically penetrates the second mold and holds the cylindrical portion of the workpiece from below, and an urging means that is inserted through the sleeve and urges the plug mold upward. The swing forging device according to claim 2 , comprising: Wherein the first type, any upper portion of the plug type for fitting with a gap that can tolerate the swing rotation, claim 1, characterized in that the recesses are provided 3 The swing forging device according to claim 1. The first mold is swung and rotated with a predetermined center point as a reference, and a disk-shaped workpiece having a cylindrical portion formed with multi-stage inner peripheral surfaces is set on the second mold, and the first mold and the second mold are set. A swing forging method for forming the workpiece by bringing the workpiece into contact with the first die by separating and approaching the die,
A plug mold that is separate from the first mold and the second mold is formed so that an outer peripheral shape thereof is a multi-stage cylindrical shape that follows an inner peripheral surface of the cylindrical portion of the workpiece. By inserting the mold into the inner peripheral surface of the cylindrical portion of the workpiece, the center axis of the workpiece and the center axis of the plug mold are matched,
Further, forming a molding surface related to a disk-shaped part of the workpiece and a through hole into which the cylindrical portion of the workpiece is inserted in the second mold, and setting the workpiece in the second mold, With the work interposed, the center axis of the plug mold is aligned with the center axis of the vertical direction of the second mold,
The plug mold is interposed so that the center axis of the plug mold can be brought into contact with the first mold together with the workpiece while maintaining the center axis aligned with the vertical center axis of the second mold. Then , the swing forging method is characterized in that the inner peripheral surface of the cylindrical portion of the workpiece is formed by the plug mold, supported from below. 6. The swing forging method according to claim 5 , wherein the plug mold is positioned in a state of being pressed against the first mold together with the workpiece. The first mold is provided with a recess for fitting the upper end of the plug mold with a gap allowing the rocking rotation, and the upper end of the plug mold is inserted and held in the recess. The swing forging method according to claim 5 or 6 .

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